Screw-threaded cap for covering glass jars and other containers and method of making same



NOV. 12, 1929. s TEVANDER 1,735,445

' SCREW THREAD ED CAP FOR CO G VERIN GLASS JARS AND OTHER CONTAINERS AND METHOD OF MAKING SAME iled Oct. 4. 1926' Patented Nov .1 2,1929 i I 1,735,445

UNITED OFFICE SWAN NILS TEVANDER, OI IlirIBFYVOOID, ILLINOIS SCREW-THREADED GA? FOR COVERING GLASS JARS AND. OTHER G ONTAINERS AND METHOD OF MAKING SAME Application filed October 4, 1926. Serial No. 139,446.

My invention relates to what are known as screw cap. Then by placing these caps in screw caps which are applied to a jar or consuitable tools here shown as comprising a tainer by screwing onto the threaded portion base block 2 in combination with radially of the jar. The object of the invention is slidingjaws Sworking against the reciprocatto provide-means for producing a cap that ing mandrel 4:, the smooth side walls 5 of the 55 may be set very tightly onto the container, blank shown in Figs. 3 and 4 are pressed so as to insure a tight seal and at the same into the threaded portions 6 of the finished time furnish means whereby the cap may be cap shown in Figs. 1 and 2. By this op- .easily released. eration the surplus metal is forced out into 10 Reference 'will be had to the accompanying ribs 7 which cross over the threaded portions 60 drawings of which Fig. 1 is an .elevation of 6 substantially in conformity with the conmy completed cap. tour or vertical section of the threaded por- Fig. 2 is a plan view thereof. tion 6.

Fig. 3 shows an elevation of the cap in the On the release of the jaws 3 from the posifirststep of forming the cap. tion shown by Figs. 6 and 7, the mandrel 65 Fig. 4 shows a plan of the cap shown in is released axially from the cap by a vertical Fig. 3.. a and revolving movement, change unscrews ig. 5 is a sectional elevation through the the cap from the mandrel.

tools showing the first position of the parts When the wrench is applied to tighten the in the operation of changing the form of the cap or release it, the wrench will engage these 7 cap shown in Figs. 3 and 4 into the finished ribs 7 and thus there is provided not merely cap shown in Figs. 1 and 2'. a frictional contact of the wrench but positive Fig. 6 shows aplan view of the parts shown means that will enable the operator to more.

in Fig. 5 at the completion of the operation easily tighten and release the cap.

2 of changing the form from that of Figs. 3 and In certain classes of packin where these 75 4 to that of Figs. 1 and 2 showingthe tools caps are screwed on very tighfiy, the releasin a closed position but with the central ingflof the cap may be assisted by ta'ppin mandrel withdrawn. J slightly onto the. ribs? and since these ribs Fig. 7 is a sectional view of the parts cross down over the threads 6 a slight tapshown in the position of Fig. 6 but with the ping on these ribs causes them to be. pushed 80 mandrel in place. inwardly and thus, 'as it were, enlarge the With the ordinary screw cap used on jars diameter, of the screw threaded portions and and other containers for preserves and other release the threads sufliciently to permit the material, when a tight seal is desired to be cap being freely unscrewed. Yet, the cap made suflicient to preserve the contents of the may be again applied and again screwed tight- 85 jar, the screw cap must be set up very tightly ly down since the amount of release affected and the ordinary screw cap, when thus used, by tapping inward the ribs 7 does not enlarge is frequently set up with a wrench in the the diameter of the screw thread portion s0 hands of the housewife. This wrench is greatly as to prevent the housewife using the usually arranged to grip the cap by friction ca as a stopper or cover for the jar or con- 90 alone and requires a person with quite a tamer while the contents of the same are strong grip of the hand. Then to release bein' consumed, a portion at a time. such a cap the same sort of a wrench is gen- W at I claim is erally used, but after the jar has been stand- 1. The method of forming a screw thread.-

ing a long timeoften fora year or moreed cap from a flanged blank which consists 9 the cap sticks so tightly that it is difficult to in inserting a threaded mandrel in the blank, get it free. then causing a plurality of correspondingly In the formation of my cap I draw up the threaded, radially movable, segmental dies blanks to the form of Figs. 3 and 4; which is to close about the flange of the blank and larger than would be desired for an ordinary press the latter into the threads of the man drel, said Segmental dies being dimensioned to leave spaces between them 1n closed position into which the excess material of the flange is forced outwardly to form outwardly projecting ribs or folds extending across the threads of the flange.

2. In the method of forming a screw threaded cap as defined inclaim 1, releasing the finished cap by unscrewing the mandrel therefrom and then radially withdrawing the segmental dies.

3. The method of forming a screw threaded ca with ribs disposed at intervals crossing its t reads which consists in providing a flanged blank, inserting a threaded mandrel therein and applying radial pressure externally to the flange over a plurality of spaced segments thereof, thus causing said segments to conform to the flangedmandrel and permitting vthe intermediate portions of the flange to compose ribs projecting from the external threaded surfaces of the flange and extending transversely of .the threads thereon.

4. The method of producing a screwthreaded cap which consists in first forming a flanged blank with a flange of larger diameter than is wanted in the finished cap, then press ing spaced segments of the flange radially inward while permitting the material in the spaces to bend or buckle to form outwardly projecting radial ribs, the inward pressure beingexerted against a threaded mandrel, whereby threads are formed in the segmental portions of the flange simultaneously with the formation of said ribs.

5. The method of producing a screwthreaded cap which consists in first forming a flanged blank with a flange of larger diameter than is wanted in the finished cap, then pressing spaced segments of the flange radially inward against a threaded mandrel while permitting the material in the spaces to bend or buckle outwardly without any substantial stretching of said material, thus forming radially projecting ribs at intervals between the thread portions of the flange.

6. A flanged sheet metal cap having a screw thread pressed in spaced segments of its flange and separated by ribs which extend transversely of the direction of the threads, and which consist of athered portions of the material crimped or excessive sides of the flanged blank, and thus comprlsing material which has been subjected to substantially no more stretching strain than the remaming material of the flange.

Si ed at Chicago,

in the county of Cook and bite of Illinois ent to project radially outward, said ribs representing the initially this 27th day of Sept,

SWAN NILS TEVANDER. 

